:root{
  color-scheme: dark;
  font-family: "Helvetica Neue",Helvetica,Arial,sans-serif;
}

/* TITLE */
h3{
  font-size: 21px;
  color: violet;
}

/* BOX-TEXT */
#box-text{
    padding: 2%;
    margin: 1%;
    text-align: center;
    box-shadow: rgba(0, 0, 0, 0.3) 0px 19px 38px, rgba(0, 0, 0, 0.22) 0px 15px 12px;
}

/* INPUT SIDE */
#input-div{
    position: absolute;
    left: 0%;
    right: 50%;
    margin: 1%;
    margin-top: 0.5px;
    padding: 2%;
    width: 45%;
}

/* OUTPUT SIDE */
#output-div{
    position: absolute;
    right: 1%;
    left: 50%;
    margin: 1%;
    margin-top: 0.5px;
    padding: 2%;
    width: 45%;
}

/* USER INPUT COLOR */
span{
  color: violet;
}

/* BUTTON */
.button-calc, input{
  padding: 0.6em 2em;
  margin: 1%;
  border: none;
  outline: none;
  color: rgb(255, 255, 255);
  background: #111;
  position: relative;
  z-index: 0;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;;
}

.button-calc{
  width: 50%;
  height: 40px;
  margin-bottom: 2.5%;
  border-radius: 10px;
}

input{
  border-bottom-style: dashed;
  border-bottom-width: 2.5px;
  border-bottom-color: violet;
  font-size: 15px;
  width: 30%;
}

.button-calc{
  cursor: pointer;
}

.button-calc:before{
  content: "";
  background: linear-gradient(
    45deg,
    #ff0000,
    #ff7300,
    #fffb00,
    #48ff00,
    #00ffd5,
    #002bff,
    #7a00ff,
    #ff00c8,
    #ff0000
  );
  position: absolute;
  top: -2px;
  left: -2px;
  background-size: 400%;
  z-index: -1;
  filter: blur(5px);
  -webkit-filter: blur(5px);
  width: calc(100% + 4px);
  height: calc(100% + 4px);
  animation: glowing-button-calc 20s linear infinite;
  transition: opacity 0.3s ease-in-out;
  border-radius: 10px;
}

@keyframes glowing-button-calc {
  0% {
    background-position: 0 0;
  }
  50% {
    background-position: 400% 0;
  }
  100% {
    background-position: 0 0;
  }
}

.button-calc:after{
  z-index: -1;
  content: "";
  position: absolute;
  width: 100%;
  height: 100%;
  background: #222;
  left: 0;
  top: 0;
  border-radius: 10px;
}